Total bridges
113
Public highway bridges in Powell County
County profile · official public datasets
Powell County, MT
113 public highway bridges tracked in the FHWA National Bridge Inventory: 25.7% rated Good, 68.1% Fair, 6.2% Poor.
- 113
- Public bridges
- 25.7%
- Good condition
- 6.2%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Powell County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 30th
- of 56 on Poor share
- 6.2%
- Poor-condition share
- 113
- public highway bridges
- 1981
- avg year built
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
Powell County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Powell County ranks #30 of 56 Montana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.2%). Powell County, Montana contains 113 public highway bridges. Roughly 25.7% are rated “Good,” 68.1% “Fair,” and 6.2% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Good condition
25.7%
29 of 113 rated 7-9
Fair condition
68.1%
77 of 113 rated 5-6
Poor condition
6.2%
7 of 113 rated 4 or below
In-state Poor-share rank
#30 of 56
Among Montana counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 113 NBI-tracked bridges by lowest applicable component rating.
Good 25.7% (29)
Fair 68.1% (77)
Poor 6.2% (7)
Powell County's Poor-condition bridges carry 18,778 vehicle crossings a day
That is 8.6% of the county's reported daily bridge traffic on 6.2% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,683 crossings a day against 642 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 113 of 113 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
41.6% of Powell County's bridges have passed the 50-year mark
47 of the 113 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 25.7% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
One structure carries 31.5% of the county's Poor-condition bridge traffic
I 90 EB over RR, built 1973, carries 5,915 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 7-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 18,778 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Powell County's bridges were built
113 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 1
1910–1919
1 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 4
1940–1949
4 bridges
- 1950s
1950–1959
12 bridges
- 1960s
1960–1969
14 bridges
- 1970s
1970–1979
23 bridges
- 1980s 9
1980–1989
9 bridges
- 1990s 7
1990–1999
7 bridges
- 2000s
2000–2009
21 bridges
- 2010s
2010–2019
12 bridges
- 2020s 4
2020–2029
4 bridges
What this shows Construction peaked in the 1970s, when 23 of the county's bridges still in the inventory were built, which is 20.4% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1981) matches the Montana average (1977).
How Powell County compares with Montana's closest counties by inventory size
The 5 Montana counties nearest Powell County in number of bridges, with their condition splits. Its 6.2% Poor share is the 2nd-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1979 is in line with the group.
Showing the 5 closest of 55 Montana counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Sanders County | 120 | 40% | 52.5% | 7.5% | 1979 |
| Lake County | 117 | 57.3% | 27.4% | 15.4% | 1995 |
| Rosebud County | 114 | 18.4% | 76.3% | 5.3% | 1973 |
| Powell County (this page) | 113 | 25.7% | 68.1% | 6.2% | 1981 |
| Dawson County | 109 | 8.3% | 85.3% | 6.4% | 1972 |
| Valley County | 104 | 10.6% | 76.9% | 12.5% | 1975 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Powell County's. Source: FHWA National Bridge Inventory, 2024 release.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Powell County, both outside Montana so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MT (113 bridges here).
- Lake County, FL · 113 bridges
- Chattooga County, GA · 113 bridges
- Jersey County, IL · 113 bridges
- Tipton County, IN · 113 bridges
Similar average build year
Nearest mean year-built outside MT (1981 here).
- Franklin County, OH · avg 1981 · 922 bridges
- Greenville County, SC · avg 1981 · 635 bridges
- Montgomery County, OH · avg 1981 · 632 bridges
- McLean County, IL · avg 1981 · 624 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (77)
I 90
FairOver: SEP MILWAUKEE AVENUE
DEER LODGE, Powell, MT
Built 1961 Load: 32.7 t ADT: 4,928
I 90
FairOver: SEP EASTSIDE ROAD
0.6M S DEER LODGE, Powell, MT
Built 1961 Load: 32.7 t ADT: 4,928
SAWMILL RD
FairOver: CLARK FORK RIVER 026
GARRISON, Powell, MT
Built 2006 Load: 32.7 t ADT: 77
RAYMOND RD
FairOver: BLACKFOOT RIVER 077
6M S OVANDO, Powell, MT
Built 1997 Load: 32.7 t ADT: 100
S 271
FairOver: NEVADA CREEK
1M NE HELMVILLE, Powell, MT
Built 1947 Load: 32.7 t ADT: 302
I 90
FairOver: SEP GARRISON FRONTAGE RD
2.5M W GARRISON, Powell, MT
Built 1973 Load: 33.6 t ADT: 5,070
I 90
FairOver: SEP GARRISON FRONTAGE RD
2.5M W GARRISON, Powell, MT
Built 1973 Load: 33.6 t ADT: 5,070
I 90
FairOver: JR GRADE SEP
6.2M N DEER LODGE, Powell, MT
Built 1961 Load: 33.6 t ADT: 10,329
2801: CHAMBERLAIN
FairOver: East Fork Chamberlain Cr
38 MI W of Missoula MT, Powell, MT
Built 2008 Load: 34.3 t ADT: 25
RAMP TO MAIN ST
FairOver: INT S DEER LODGE-I 90
1M S DEER LODGE, Powell, MT
Built 1961 Load: 34.5 t ADT: 100
I 90
FairOver: CLARK FORK RIVER
1.2M S DEER LODGE, Powell, MT
Built 1961 Load: 35.4 t ADT: 4,928
MAIN ST
FairOver: CLARK FORK RIVER
S DEER LODGE, Powell, MT
Built 1949 Load: 35.6 t ADT: 2,287
I 90
FairOver: INT E GARRISON-RR
1.2M S GARRISON, Powell, MT
Built 1979 Load: 36.3 t ADT: 5,165
ROAD
FairOver: RACETRACK CR
RACETRACK CREEK, Powell, MT
Built 1985 Load: 36.9 t ADT: 40
I 90
FairOver: INT E GARRISON-RR
1.2M S GARRISON, Powell, MT
Built 1979 Load: 37.2 t ADT: 5,165
US 12
FairOver: LITTLE BLACKFOOT RIVER
GARRISON, Powell, MT
Built 1952 Load: 37.2 t ADT: 1,377
E SAGER LN
FairOver: CLARK FORK RIVER 048
5M S DEER LODGE, Powell, MT
Built 2006 Load: 39.0 t ADT: 100
US 12
FairOver: LITTLE BLACKFOOT RIVER
1M E ELLISTON, Powell, MT
Built 1988 Load: 40.8 t ADT: 3,311
BURNS ST
FairOver: LITTLE BLACKFOOT R 019
N ELLISTON, Powell, MT
Built 1960 Load: 41.7 t ADT: 276
US 12
FairOver: LITTLE BLACKFOOT RIV-RR
5M E GARRISON, Powell, MT
Built 2009 Load: 41.7 t ADT: 3,129
NO DATA ENTERED
FairOver: LODGEPOLE CR
SPRUCE CR, Powell, MT
Built 1996 Load: 42.1 t ADT: 40
S MULLAN TRAIL RD
FairOver: CLARK FORK RIVER 030
9M E DRUMMOND, Powell, MT
Built 2003 Load: 43.4 t ADT: 100
CLARK ST
FairOver: COTTONWOOD CREEK 083
DEER LODGE-CLARK ST, Powell, MT
Built 2007 Load: 44.5 t ADT: 244
NO DATA ENTERED
FairOver: WEST FORK SPRUCE CREEK
NO DATA ENTERED, Powell, MT
Built 2020 Load: 68.0 t ADT: 50
NO DATA ENTERED
FairOver: EF SPRUCE CREEK
NO DATA ENTERED, Powell, MT
Built 2020 Load: 69.0 t ADT: 50
S MULLAN TRAIL RD
FairOver: RR 028
9M E DRUMMOND, Powell, MT
Built 2000 Load: 79.8 t ADT: 100
I 90
FairOver: DEMPSEY CREEK
N SAGER LANE OVERPASS, Powell, MT
Built 1973 Load: 99.9 t ADT: 10,571
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.